1. Field of the Invention
The present invention relates to displaying and/or browsing a data set in a multi-faceted way. In particular, to a method and device for 3D displaying and/or browsing a data set from multiple facets each of which is a hierarchy of subject labels.
2. Description of the Related Art
Metadata is information about information. In many cases, a set of hierarchical subject labels is used as metadata for categorizing resources, e.g., Yahoo Directory and ODP (Open Directory Project). A multi-faceted browsing interface introduces multiple orthogonal sets of hierarchical subject labels to categorize resources and enables the user to narrow the scope of resources from different points of view via selecting subject labels in different facets. Multi-faceted browsing has been proven an efficient and interactive way to access resources and has been implemented for browsing a lot of web resources. For example, in some mp3 repository web sites, songs are categorized by artists, genres, region, length, etc. The user can select subject labels under these facets to narrow the scope and find songs of his/her interest. For example, if the user selects the “Region” facet, the subject labels like “North America”, “Europe”, etc. under the “Region” facet are displayed, and the user can select one certain subject label to narrow the searching scope from this geography facet.
In most multi-faceted browsing interfaces, subject labels under the same parent node are displayed as a text list and ranked by the number resource items under them. This kind of approaches has two major disadvantages: first, this straight list style display is not capable of demonstrating complex information, i.e., relationships between subject labels, the relativities between subject labels and user's profile, etc.; second, when there are too many subject labels under a facet category, the list will become too long for the screen to display and this disadvantage will become even worse in small screen devices such as mobile phones.
To illustrate the above disadvantages, the Flamenco Search Interface (see http://flamenco.berkely.edu/demos.html, which is accessible as of Jan. 24, 2011) has implemented a multi-faceted browsing interface on the data set of Nobel Prize Winners, as shown in FIG. 1, which provides data searching for Nobel Winners over the past years from many facets (including “Gender”, “Prize”, “Country”, “Year”). In FIG. 1, the subject labels under each facet are displayed as a text list. For example, under the facet “Country”, subject labels “America”, “China”, “Japan”, etc (countries owning prize winners) are displayed as a list; under the facet “Year”, subject labels “1910-1920”, “1920-1930”, etc. (when the prizes were awarded) are displayed as a list; under the facet “Prize”, subject labels such as prize types “Physics”, “Chemistry”, etc, are listed. The above-mentioned solution cannot display complex information, such as, which subject label is more important or the relationships between the subject labels. For example, the relativities between countries can be represented by the geographical distances between their capitals but the list display style is not complex enough to represent such information. Also, the list is too long to be displayed in a small screen. Although a number of solutions have been proposed to improve multi-faceted browsing interface usage in a screen of small size, they are mostly 2D based solutions and cannot represent the complex information mentioned above.